Simultaneous Enzymatic Synthesis of Gluconic Acid and Sorbitol
The production of sorbitol and gluconic acid by isolated glucose-fructose oxidoreductase (GFOR) from Zymomonas mobilis has been studied in a connective, 100-mL loop reactor with tangential ultrafiltration. Using a dilution rate of 0.04/h and 5 kU/L GFOR, substrate conversion (3 M sugar) in a single stage was >85%, and productivities of 126 g sorbitol/(L·d) were obtained. At a constant recycle rate (3/min) and a membrane area of 50 cm2, the dilution rates (and thus productivities) were however limited by a more than 30-fold reduction of the permeate flow in the presence of high sugar and protein concentrations (5 g/L). Protein was added, together with 10 mM dithiothreitol, to improve the stability of GFOR during substrate turnover and crossflow filtration, thus leading to a stable operation of the enzyme reactor for at least 5 d.
Index EntriesGlucose-fructose oxireductase sorbitol gluconic acid zymomonas mobilis
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- 2.Zachariou, M., and Scopes, R. K. (1986), J. Bacteriol. 167, 863–869.Google Scholar
- 6.Ichikawa, Y., Kitamoto, Y., Kato, N., and Mori, N. (1988), EP 0 322 723 A2.Google Scholar
- 8.Roh, H.-S. and Kim, H.-S. (1992), Enzyme Microb. Technol. 13, 920–924.Google Scholar
- 11.Scopes, R. K., Rogers, P. L., and Leigh, D. A (1988), US Patent 4755467.Google Scholar
- 15.Fürlinger, M., Haltrich, D., Kulbe, K. D., and Nidetzky, B. (1998), Eur. J. Biochem., in press.Google Scholar